• International Journal of Precision Engineering and Manufacturing
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• v.9 no.4
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• pp.32-38
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• 2008

This paper describes a fast tool control (FTC)-based diamond turning process for fabricating large-area high-quality micro-lens arrays. The developed FTC unit has a stroke of $48{\mu}m$ and a resonance frequency of 4.9 kHz. Micro-lens arrays were fabricated using a micro-cutting tool with a nose radius of $50{\mu}m$. The FTC unit was integrated with a force sensor so that the initial position of the micro-cutting tool with respect to the workpiece surface could be detected through monitoring the contacting force. The length and depth of the designed parabolic micro-lens profile were $190{\mu}m$ and $20{\mu}m$, respectively. A micro-lens array was fabricated on a cylinder surface over an area of ${\phi}55 mm{\times}40 mm$.

• Journal of Communications and Networks
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• v.13 no.2
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• pp.86-94
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• 2011

In recent years, there has been a rise in epidemiological evidence suggesting the health benefits of a physically active lifestyle. However, it is not always easy for individuals to personally recognize the optimal conditions for exercise and physical activity. Wearable acceleration-based pedometers have become widely used in estimating the amount of physical activity, and to a limited extent, providing information regarding exercise intensity, but they have never been used to assess adaptation to exercise. In order to realize simultaneous activity monitoring for multiple users exercising outdoors, we developed a prototype wireless local area network (WLAN) based system. In our system, a WLAN is deployed outside, and a user wearing a smart phone and monitoring device exercises freely within the coverage area of the wireless network. By doing so, the developed system is able to monitor the activity of each user andmeasures various parameters including those related to exercise adaptation. In a demonstration experiment, the developed system was evaluated and used to monitor users enjoying a Nordic walk, after which users were immediately able to receive their exercise report. In this paper, we discuss the requirements and issues in developing an activity monitoring system and report the findings we obtained through the demonstration experiment.

• Journal of the Korean Association of Geographic Information Studies
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• v.14 no.4
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• pp.137-149
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• 2011

In this study, we analyzed the effects of seismic displacements due to the mega thrust earthquake occurred near Tohoku-Oki area on Mar. 11, 2011 with Mw 9.0 magnitude in the context of evaluation of position change by the earthquake on the Korean and Asian GPS permanent stations. For this, two weeks GPS data observed around the event of Tohoku-Oki earthquake (Mar. 4 ~ Mar. 18, 2011) were obtained from 22 GPS permanent stations in the vicinity of epicenter (Korea, Japan, Russia, China and Taiwan) and 284 IGS global stations. All available GPS data were processed and adjusted by GAMIT/GLOBK software to estimate the co-seismic horizontal displacements at each station. As the results of GPS analysis, the co-seismic displacements due to Tohoku-Oki earthquake were clearly revealed in the GPS stations of Asian region, Japan and its neighboring countries, and even to affect the horizontal position of GPS station (WUHN in China) which are located about 2,702km away from the epicenter. In conclusion, it was found that the Tohoku-Oki earthquake had resulted in the horizontal displacements ranging from 14.9 mm to 58.3 mm in Korea. So, these displacements can cause the position error of GPS geodetic survey up to 20 mm without updating the coordinates of Korean geodetic network.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.33 no.6
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• pp.497-506
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• 2015

Gravity variations due to the 2011 Tohoku (M9.0) earthquake, which occurred at the plate boundaries near the northeastern coast of Japan, were estimated through the GRACE spherical harmonic (Stokes) coefficients derived from the CSR. About -5 μGal gravity variation by the GRACE data was found in the back-arc basin area with respect to a reference gravity model. The mean gravity variations in the back-arc basin area and the Japan Trench area were -4.4 and -3.2 μGal in order. The small negative gravity variations around the Japan Trench area can be interpreted by both crustal dilatation and the seafloor topography change in comparison with the large negative gravity variations in the back-arc basin area by co-seismic crustal dilatation of the landward plate. From the results of the gravity variations, vertical displacements generated from relatively short wavelength caused by the earthquake were estimated by use of multi-beam bathymetric measurements obtained from JAMSTEC. The maximum seafloor topography changes of about ±50 m were found at west side of the Japan Trench axis by the earthquake. The seafloor topography change by the megathrust earthquake can be considered as the results of the landslide of the seafloor throughout the landward side.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.46-46
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• 2017

We developed a rice simulation model for remote-sensing (SIMRIW-RS, Homma et al., 2007) to evaluate rice production and management on a regional scale. Here, we reports its application trial to estimate rice production in farmers' fields in Sendai, Japan. The remote-sensing data for the application was periodically obtained by multispectral camera (RGB + NIR and RedEdge) attached with unmanned air vehicle (UAV). The airborne images was 8 cm in resolution which was attained by the flight at an altitude of 115 m. The remote-sensing data was relatively corresponded with leaf area index (LAI) of rice and its spatial and temporal variation, although the correspondences had some errors due to locational inaccuracy. Calibration of the simulation model depended on the first two remote-sensing data (obtained around one month after transplanting and panicle initiation) well predicted rice growth evaluated by the third remote-sensing data. The parameters obtained through the calibration may reflect soil fertility, and will be utilized for nutritional management. Although estimation accuracy has still needed to be improved, the rice yield was also well estimated. These results recommended further data accumulation and more accurate locational identification to improve the estimation accuracy.

• Journal of Ecology and Environment
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• v.41 no.3
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• pp.54-65
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• 2017

Background: "Igune," a traditional agricultural landscape in the Tohoku region of Japan, is characterized by small-scale artificial woodlots surrounding a farmer's house that are interspersed with paddy fields. During the rapid economic growth of Japan over recent decades, some igune woodlots have been abandoned or logged. Biodiversity conservation is an important issue worldwide, and traditional agricultural landscapes are of particular interest. To elucidate the role of igune landscapes in conserving biodiversity, we examined the effects of environmental factors on avian communities. Results: The study was conducted in the suburban areas of Oshu and Hanamaki cities, Iwate Prefecture, Japan, at eight sites that varied in the density and area of igune woodlots within the landscape. Bird surveys were conducted from the middle to late breeding season, and several environmental factors of the igune landscape were also measured. The results of canonical correspondence analysis indicated that the characteristics of avian communities were mainly determined by the total forested area in the landscape. Increased total forested area and shrubs layer of igune woodlots did not cause a reduction in number of bird species of any habitat and foraging types, while increased both in species number and abundance of insectivores and forest species. The number of raptor species increased in igune sites without shrubs. Conclusions: Our results suggest that maintaining igune landscapes may enhance avian diversity within this landscape, although the effects of shrubs within igune varied; developed bush communities increased the evenness of the avian community, whereas some raptor species preferred an open forest understory.

• Proceedings of the KACD Conference
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• 2003.11a
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• pp.546.1-546
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• 2003

Laser doppler flowmeter (LDF) has been applied to the measurement of pulpal blood flow (PBF) in human teeth. As far as we searched, the detection area of the pulp in the blood flow measurement has not been clarified, yet. Therefore, the purpose of this study was to obtain information of the detection area in PBF measurement using LDF. The experiments were performed on the artificial blood circulation in extracted human upper central incisors. The apical portions of examined teeth (n=6) were severed and root canals were enlarged from the apical end to the 2mm incisal to the level of enamel-cement junction. An individual resin cap of each tooth was prepared and a hole was drilled 2mm incisal to enamel-cement junction of the labial side of the cap. The measurement probe of LDF (MBF3D, Moor Instrument, UK) was plugged into the hole of the cap. Heparinized human peripheral blood, which was in advance collected and diluted 3 times with physiological saline, was pumped through the apical foramen of the teeth via a silicone tube and a disposable needle (o.d. 0.7mm) and blood flow signals were monitored. The flux signal significantly increased with the enlargement of the root canal to incisal direction (p<0.01, Friedman analysis). The result indicates that the performance of LDF in PBF with human teeth is limited.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.75-75
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• 2022

Traditional agriculture mostly focused on activity in the field, but current agriculture faces problems such as reduction of agricultural inputs, labor shortage and so on. Accordingly, traditional agricultural experiments generally considered the simple treatment effects, but current agricultural experiments need to consider the several and complicate treatment effects. To analyze such several and complicate treatment effects, data collection has the first priority. Remote sensing is a quite effective tool to collect information in agriculture, and recent easier availability of UAVs (Unmanned Aerial Vehicles) enhances the effectiveness. LAI (Leaf Area Index) is one of the most important information for evaluating the condition of crop growth. In this study, we utilized UAV with multispectral camera to evaluate plant-based LAI of sweetcorn in a small-scale field experiment and discussed the feasibility of a new experimental design to analyze the several and complicate treatment effects. The plant-based SR measured by UAV showed the highest correlation coefficient with LAI measured by a canopy analyzer in 2018 and 2019. Application of linear mix model showed that plant-based SR data had higher detection power due to its huge number of data although SR was inferior to evaluate LAI than the canopy analyzer. The distribution of plant-based data also statistically revealed the border effect in treatment plots in the traditional experimental design. These results suggest that remote sensing with UAVs has the advantage even in a small-scale experimental plot and has a possibility to provide a new experimental design if combined with various analytical applications such as plant size, shape, and color.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.215-215
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• 1996

The present study examined chronic effects of transient focal cerebral ischemia on the substantia nigra, a remote exofocal area, using immunohistochenmical and receptor autoradiographic techniques. Transient focal cerebral ischemia was induced by middle cerebral artery (MCA) occlusion for 60 or 90 min followed by reperfusion using silicone-coated 4-0 nylon monofilament in male Wistar rats. After 1- or 2-week reperfusion following transient MCA occlusion, there were partial losses of tyrosine hydroxylase-immunoreactive dopaminergic neurons, incieases in glial fibrillary acidic protein-immunoreactive cells (gliosis), decreases in [$^3$H]YM-09151-2 binding for dopamine D$_2$ receptors, and marked atrophy in the ipsilateral substantia nigra. The precise mechanism(s) of exofocal damage to the substantia nigra is remained to be elucidated.

• Tribology and Lubricants
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• v.5 no.1
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• pp.36-43
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• 1989

Scanning electron microscopic observations were carried out on the worn surface and the wear debris of ceramic materials to investigate the wear mechanism of those in dry rolling contact. It was found from the scanning electron microscopic observations that the wear in ceramic materials is related to brittle fracture and has two types of wear mechanisms, small scale wear and larvae scare wear. Plate-like wear debris were created from the initial surface cracks and defects. The small scale wear was related to real contact area and large scale wear was related to HertzJan contact area. A wear model was proposed on the basis of scanning electron microscopic observations.